From the US-document U.S. Pat. No. 7,556,615 B2, for example, a microneedle access device is known, which is provided with a protruding ring-shaped skin pre-stressing device. This skin pre-stressing device encloses the microneedle, and it touches the skin surface of the patient before puncturing the skin, shortly after the microneedle deformed the skin through contact. With the ring-shaped skin pre-stressing device, the deformation of the skin surface is minimized, which allows for a more precise penetration of the microneedle.
Further, from the international patent application publication WO 2007/061972 A2 an access device for injectable substances is known, that is provided with a hollow needle of sufficient length in order to penetrate into the skin of a patient. The access device is provided with a delimiter for controlling the penetration depth of the hollow needle as well as a stabilizer that is positioned at a distance to the delimiter. Deformation of the tissue close to the puncture position is avoided with the stabilizer, so that the depth where the substance is introduced is essentially determined through the length of the hollow needle.
The US-document US 2004/0147901 A1 discloses an intradermal application device, provided with a vacuum chamber in order to achieve an essentially flat puncture area for the hollow needle on the skin. The angle between the axis of the device and the skin is 45° in one embodiment, but can be every angle between 30° and 60° in other embodiments.
Further, from an international patent application publication WO 2009/086463 A1 a device for applying a substance is known, which is provided with a sealed package with a squeezable reservoir, containing the substance. Further, a hollow needle is envisioned for the application of the substance, which is a therapeutic liquid.